scholarly journals Transport of γ-aminobutyrate and l-glutamate into synaptic vesicles. Effect of different inhibitors on the vesicular uptake of neurotransmitters and on the Mg2+-ATPase

1991 ◽  
Vol 276 (2) ◽  
pp. 363-367 ◽  
Author(s):  
E M Fykse ◽  
F Fonnum
Keyword(s):  
Benzoic Acid ◽  
Rat Brain ◽  
Synaptic Vesicles ◽  
Glutamate Uptake ◽  
Gaba Uptake ◽  
Anion Channels ◽  
Low Concentrations ◽  
Lipophilic Anion ◽  
Vesicular Uptake ◽  
Disulphonic Acid

The uptakes of gamma-aminobutyrate (GABA) and L-glutamate into synaptic vesicles isolated from rat brain were compared with respect to the effects of 4-acetamido-4′-isothiocyanostilbene-2,2′- disulphonic acid (SITS), 4,4′-di-isothiocyanostilbene-2,2′-disulphonic acid (DIDS) and 5-nitro-2-(3-phenylpropylamino)benzoic acid (N144), agents known to block anion channels. The uptake of glutamate was inhibited by low micromolar concentrations of SITS, DIDS and N144. GABA uptake was much less sensitive to these agents than was glutamate uptake. SITS and N144 inhibited the vacuolar H(+)-ATPase of synaptic vesicles to a smaller extent than the glutamate uptake. The uptake of GABA was not affected by the permeant anions Cl- and Br-, whereas the uptake of glutamate was highly stimulated by low concentrations of these ions. The uptakes of both glutamate and GABA were inhibited by similar, but not identical, concentrations of the lipophilic anion SCN-.

The effects of ebselen on [3H]glutamate uptake by synaptic vesicles from rat brain

2004 ◽  
Vol 1027 (1-2) ◽  
pp. 192-195 ◽  
Author(s):  
Lisiane O. Porciúncula ◽  
João Batista T. Rocha ◽  
Gabriele Ghisleni ◽  
Rejane G. Tavares ◽  
Diogo O. Souza
Keyword(s):  
Rat Brain ◽  
Synaptic Vesicles ◽  
Glutamate Uptake

Inhibition of glutamate uptake into synaptic vesicles of rat brain by the metabolites accumulating in maple syrup urine disease

2000 ◽  
Vol 181 (1-2) ◽  
pp. 44-49 ◽  
Author(s):  
Rejane G Tavares ◽  
Candice E.S Santos ◽  
Carla I Tasca ◽  
Moacir Wajner ◽  
Diogo O Souza ◽  
...  
Keyword(s):  
Rat Brain ◽  
Maple Syrup Urine Disease ◽  
Synaptic Vesicles ◽  
Glutamate Uptake ◽  
Maple Syrup ◽  
Urine Disease

Quinolinic Acid-induced Seizures Stimulate Glutamate Uptake into Synaptic Vesicles from Rat Brain: Effects Prevented by Guanine-based Purines

2007 ◽  
Vol 33 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Rejane G. Tavares ◽  
André P. Schmidt ◽  
Carla I. Tasca ◽  
Diogo O. Souza
Keyword(s):  
Rat Brain ◽  
Quinolinic Acid ◽  
Synaptic Vesicles ◽  
Glutamate Uptake

scholarly journals Glutamate uptake into synaptic vesicles of bovine cerebral cortex and electrochemical potential difference of proton across the membrane

1989 ◽  
Vol 258 (2) ◽  
pp. 499-504 ◽  
Author(s):  
J Shioi ◽  
S Naito ◽  
T Ueda
Keyword(s):  
Cerebral Cortex ◽  
Synaptic Vesicles ◽  
Driving Force ◽  
Significant Contribution ◽  
Atp Hydrolysis ◽  
Glutamate Uptake ◽  
Protonmotive Force ◽  
Chromaffin Granule ◽  
Carbonyl Cyanide ◽  
Disulphonic Acid

Measurements have been made of the ATP-dependent membrane potential (delta psi) and pH gradient (delta pH) across the membranes of the synaptic vesicles purified from bovine cerebral cortex, using the voltage-sensitive dye bis[3-propyl-5-oxoisoxazol-4-yl]pentamethine oxanol and the delta pH-sensitive fluorescent dye 9-aminoacridine respectively. A pre-existing small delta pH (inside acidic) was detected in the synaptic vesicles, but no additional significant contribution by MgATP to delta pH was observed. In contrast, delta psi (inside positive) increased substantially upon addition of MgATP. This ATP-dependent delta psi was reduced by thiocyanate anion (SCN-), a delta psi dissipator, or carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP), a protonmotive-force dissipator. Correspondingly, a substantially larger glutamate uptake occurred in the presence of MgATP, which was inhibited by SCN- and FCCP. A nonhydrolysable analogue of ATP, adenosine 5′-[beta gamma-methylene]triphosphate, did not substitute for ATP in either delta psi generation or glutamate uptake. The results support the hypothesis that a H+-pumping ATPase generates a protonmotive force in the synaptic vesicles at the expense of ATP hydrolysis, and the protonmotive force thus formed provides a driving force for the vesicular glutamate uptake. The delta psi generation by ATP hydrolysis was not affected by orthovanadate, ouabain or oligomycin, but was inhibited by N-ethylmaleimide, quercetin, trimethyltin, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole and 4-acetamido-4′-isothiocyanostilbene-2,2′-disulphonic acid. These results indicate that the H+-pumping ATPase in the synaptic vesicle is similar to that in the chromaffin granule, platelet granule and lysosome.

scholarly journals Unique pH dynamics in GABAergic synaptic vesicles illuminates the mechanism and kinetics of GABA loading

2016 ◽  
Vol 113 (38) ◽  
pp. 10702-10707 ◽  
Author(s):  
Yoshihiro Egashira ◽  
Miki Takase ◽  
Shoji Watanabe ◽  
Junji Ishida ◽  
Akiyoshi Fukamizu ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Hippocampal Neurons ◽  
Glutamate Uptake ◽  
Ph Sensor ◽  
Mammalian Brain ◽  
Gaba Uptake ◽  
Inhibitory Neurotransmitter ◽  
Luminal Ph ◽  
Time Required ◽  
Kinetics Of

GABA acts as the major inhibitory neurotransmitter in the mammalian brain, shaping neuronal and circuit activity. For sustained synaptic transmission, synaptic vesicles (SVs) are required to be recycled and refilled with neurotransmitters using an H+ electrochemical gradient. However, neither the mechanism underlying vesicular GABA uptake nor the kinetics of GABA loading in living neurons have been fully elucidated. To characterize the process of GABA uptake into SVs in functional synapses, we monitored luminal pH of GABAergic SVs separately from that of excitatory glutamatergic SVs in cultured hippocampal neurons. By using a pH sensor optimal for the SV lumen, we found that GABAergic SVs exhibited an unexpectedly higher resting pH (∼6.4) than glutamatergic SVs (pH ∼5.8). Moreover, unlike glutamatergic SVs, GABAergic SVs displayed unique pH dynamics after endocytosis that involved initial overacidification and subsequent alkalization that restored their resting pH. GABAergic SVs that lacked the vesicular GABA transporter (VGAT) did not show the pH overshoot and acidified further to ∼6.0. Comparison of luminal pH dynamics in the presence or absence of VGAT showed that VGAT operates as a GABA/H+ exchanger, which is continuously required to offset GABA leakage. Furthermore, the kinetics of GABA transport was slower (τ > 20 s at physiological temperature) than that of glutamate uptake and may exceed the time required for reuse of exocytosed SVs, allowing reuse of incompletely filled vesicles in the presence of high demand for inhibitory transmission.

Methylmercury inhibits glutamate uptake by synaptic vesicles from rat brain

Neuroreport ◽  
2003 ◽  
Vol 14 (4) ◽  
pp. 577-580 ◽  
Author(s):  
Lisiane O. Porciúncula ◽  
João Batista T. Rocha ◽  
Rejane G. Tavares ◽  
Gabriele Ghisleni ◽  
Marcelo Reis ◽  
...  
Keyword(s):  
Rat Brain ◽  
Synaptic Vesicles ◽  
Glutamate Uptake

Guanine derivatives modulate l-glutamate uptake into rat brain synaptic vesicles

2004 ◽  
Vol 44 (6) ◽  
pp. 423-431 ◽  
Author(s):  
Carla I Tasca ◽  
Tiago G Santos ◽  
Rejane G Tavares ◽  
Ana M.O Battastini ◽  
João B.T Rocha ◽  
...  
Keyword(s):  
Rat Brain ◽  
Synaptic Vesicles ◽  
Glutamate Uptake ◽  
Guanine Derivatives
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